Selector.



A. M. BULLARD.

SELECTOR.

APPLICATION FILED MAYS, 1907.

1,106,922, Patented Aug. 11, 1914.

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UNITED STATES PATENT OFFICE.

ALBERT M. BULLARD, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRICCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SELECTOR.

Application filed May 3, 1907.

To all whom it may concern:

lie it known that I, Annnn'r M. Bunnann, citizen of the United States,residing at New York, in the county of New York and State of New York,have invented; a certain new and useful Improvement in Selectors, ofwhich the following is a full, clear, concise, and exact description.

My invention relates to selectors and particularly to the mechanism foradvancing the ratchet or equivalent movable part means for bringing theretaining pawl intoengagement with the ratchet and thereby permittingthe movement of the stepping pawl into engagement with the ratchet, sothat it may be operated by a suitable electro-responsive driving device,such as astepping magnet, to effect the advance of the ratchet. Byvirtue of this construction, the stepping pawl during its period ofactivity is continuously in correct operating position, that is, indirect engagement with the ratchet, so that its travel 1S not more thanthat required to advance the ratchet one tooth and then retire andengage the next tooth, this result being obtained without sacrifice ofthe valuable feature of restoring the ratchet "and thereby itsassociated contact at any time by merely depriving the magnetcontrolling the retaining pawl of current.

I will describe my invention more particularly by reference to theaccompanying drawing which represents my invention embodied in anautomatic. telephone exchange selector.

The contact arm 1 of the selector shown is adapted to be advanced overthe line terminals by means of a ratchet" 2 suitably supported withinthe frame of the device. A retaining pawl 3 is provided for the ratchetand its movement is controlled Specification of Letters Patent.

Patented Aug. 11, 1914.

Serial No. 371,596.

by the armature of the retaining magnet 4,

being preferably pivoted upon an extension 0']: the armature of saidmagnet as shown, said retaining pawl being brought into engagement withthe teeth of the ratchet when the. armature of the retaining magnet isattracted.

A stepping pawl 5 is provided for the ratchet, means being providedunder the control of the armature of the retaining magnet for normallymaintaining said step ping pawl out ot engagement with said ratchet. Thestepping pawl is preferably pivoted upon an extension of the armature ofthe stepping magnet 6, and may carry a pin 7 at one side of its pivotadapted to be engaged by an arm 8, carried by the extension of thearmature of the retaining magnet, when said armature is retracted, tomaintainthe stepping pawl away from the ratchet.

. A spring 9 is provided adapted, when the armature of the retainingmagneFis att-ractedand the arm 8 thereby withdrawn from engagement withthe pin 7, to move the stepping pawl into engagement with the ratchet,said spring preferably extending between the stepping pawl and theextension of the armature of magnet 6. Thus when theste 'ping pawl isreleased and the armature o magnet 6 is vibrated, the spring?) will atall times maintain the stepping pawl in engagement with the ratchetduring its advance movement and its retiring movement, so that thearmature of magnet (l'need take but very short movements, and theratchet may thereby be advanced at a very high speed.

When the retaining magnet 4 is deprived of current, the armature thereofremovesthe retaining pawl from engagement with the ratchet and the arm 8engages the pin 7 to withdraw the stepping pawl from the ratchet,whereupon the contact arm and ratchet may be restored to normal positionby suitable spring mechanism.

1. The combination with a ratchet, of a retaining pawl for said ratchet,a retaining magnet, an armature for said magnet adapted when attractedto hold said retaining pawl in engagement with said ratchet, a steppingmagnet, an armature therefor, a stepping pawl pivoted to said armature,means controlled by the armature of the retaining magnet for maintainingsaid stepping pawl out of engagement with said ratchet Whenever theretaining magnet is in its normal postion, and a'spring adapted whensaid armature of the retaining magnet.

is attracted to move said stepping pawl into engagement with saidratchet, whereby the ratchet may be advanced at a high speed upon theoperation of said stepping magnet; 2. In a step-by-step device,'thecombina-' tion with a ratchet of a stepping magnet for advancing saidratchet, and retractive means for returning said ratchet to. normal, an

when the retaining magnet is deenergized and for maintaining saidstepping pawl out of engagement with said ratchet until said retainingmagnet is again energized.

'3. In combination with a ratchet, retractive means for moving saidratchet in one direction, a pawl, an operating magnet therefor formoving said ratchet in the-other direction, a pawl and operating magnettherefor for maintaining said ratchet in any of its off-normal positionsduring the stepping movement of the first named pawl, the armature ofsaid retaining magnet serving when retracted to iiftboth said pawls outof engagement with said ratchet'and to maintain them so untiljsaidretaining-magnet is -4 again energized.

In witness whereof, I hereunto subscribe my name this 29th day of AprllA. D. 1907.

ALBERT M. BULLLR l).

Witnesses FRANK U. DAVlS, ERNEST MCDERMOTT.

uo ies or this patent may be'obtamed for five cents each, by addressingthe f Commissioner of Patents,

Washington, D. 0.

